Grinder



P. T. LENNON Dec. 15, 1931.

GRINDER Fiied June 22, 1927 INVEN OR h TTORNEYS Patented Dec. l5, 1931UNITED STATES PATENT OFFICE :PATETCK T. LENNoN, or CLEVELAND,oH1o,`Ass1GNoE To THE KELLY BEAMER oom- PANY, A CORPORATION 0E oHIoGRINDER Alipncanon mea June az, 1927. serial No. 200,571.

This invention relates-to improvement in attachments for grinders yandthe like.

Heretofore many special grindersand attachments for grinders have beenprovided for the purpose of producing or sharpening cutting edges onmulti-edged tools, such, for instance, as reamers. A

It has long been recognized that if a cutter could be so shaped that thecutting edges thereon were at a greater radial distance from its axisthan any other part of its periphery, friction between the cutter andthe article being operated upon would be reduced, and power and timethus saved. f

This radial clearance, or the space between the actual periphery of thecutter blade and a cylindrical surface passing through the cuttingedges, has been frequently obtained by so presenting the blade to thegrinding wheel that the cutting edge will be slightly in advance of theline between aXes of reamer and wheel, and so the periphery of the bladewas ground to a concave form.' Apparatus has also been provided in whichthe blade is moved circu'mferentially and the grinding wheelsimultaneously advanced relative thereto, providing a convex peripheralsurface on the blade with some radial clearance. Machines forachievingthis result have been 30 provided with means, such aseccentrics, for

periodically advancing the grinding wheel relative the blade. While thismethod of providing a radial clearance produces a stronger blade thanthat of providing itA 5 with a concave peripheral surface, machines ofthis type were adapted only to the grinding of cutters in which 'theblades were evenlyrand equally spaced about the periphery.

As it is customary in reamers having axially extending blades to spacethesame unevenly in order to prevent Vchatter in service, machines lofthe type above described have been found unsatisfactory. Even in caseswhere the feed .has been controlled by cams 45 or the like, while themachine may satisfactorily grind one particular form of cutter cuttersof other makes, or other cutters of the same make made with cuttingedgesslightly.

differently arranged, could not be sharpened thereby.

By the application of my invention, it is possible to grind reamers,cutters, or the like, having peripheral blades in which the blades arenot arranged uniformly according to any definite plan, to produce aVconvex surface on the blades,.and.so provide a desired radial Figure 5is a view similar to Figure 4f, but

showing the parts in the position which they occupy whenl ust completingthe grinding of a particular tooth, and

Figure 6 is an enlarged fragmentary section showing the clearanceprovided on a cutting blade. ,l

As reamers, even when'the blades are unevenly arranged about theirperiphery, have them arranged in pairs, the members Vof each pair beingdiametrically opposite, the blade oppositethat being ground may be, andin the 'embodiment illustratedis shown as, used to control the feed ofthe workrelative the grindingwheel, althoughthe blade which is beingground could be used to equal advanj.,

tage for this purpose. Y y -v The fixture illustrated comprises a basel, adapted to be mounted on the table 2 of any suitable. grinder andprovided at. its ends with apertured lugs 3 through which bolts t To.

3 extending actuating strut or pawl 25, adaptmay be passed'to secure thebase in place. Secured to the upper. surface of the base are bearingmembers 4 and 5, which may be conveniently secured by cap screws 6, orthe like, which may pass through slots 7 in either or both bearingmembers thereby rendering the same adjustable longitudinally of thebase.

The bearing members have longitudinally aligned apertures for receivingpivot pins 8 upon which a pivoted headstock 9 and foot stock 10 may rocktoward or away from the grinding wheel 11 of the grinder. This rockingmotion constitutes the feed by which the radial clearance ony thetoothof the cutter is produced.

The upper portion of the headstock is formed to receive a bushing 12 inwhich the shank of the reamer may be directly received and rotate orwhich may receive collets or the like for holding different reamershanks. The upper end of the footstock, in longitudinal alignment withthe center of the bushing, is provided with al longitudinally adjustabledead center 13, which may be adjusted by bein-g provided with a threadedshank and nut 11i-,vas shown.

A stationary pivot 15v is supported by the bearing` members at the side`of the fixture adjacent to the grinding wheel, and carries a lever 16whichV is normally retained in an elevated position, as shown inFigures, by a spring 17. The free endv ofthe lever carries a rod v1S4extending longitudinally of the fix" ture.L Q Pivoted upon the ends ofthe rod are upwardly extending links 19 which are piv oted at theirupper ends to cranks 20, the other end of the cranks being pivoted uponthe head and footstock respectively. The pivots ,connecting the links 19with cranks 20, are extended toward the adjacent end of the fixture toconstitute crossheads 21 slidable in guideways 22 adjustably carried bystationary arms23 which may conveniently be integralwith theibearingmembers 1- and VIt will be seen that with the guide members: 22 adjustedas shown inthe drawings, that when the lever 16 is moved downwardly,this motion'is transmitted through links, 19 to the ends, of cranks 20,and as the motion of pivot and cross head 21 is in a rectilinear patin,lying within the circle which it would transcribe yif revolving freelyabout the centerl oftheistock, this motion forces the head andfootstocks simultaneously toward the grinding wheel 11, and so providesthe desired feed.

Thelever 16 carries an adjustable pivot, shown as ajbolt24, movablealong a slot in the lever, upon which lpivot is an upwardly edto beengaged by the teeth of the reamer. The upperend of the strut isprovided with a. roller 2,6 engaging an ustable guide consisting of anLeshaped member 27 secured by a slot and bolt-28 to a statOnarystandardor bracket 29 upon the base of the fixture. The strut is urgedtoward the reamer by a spring 30.

The operation of the device is as follows:

A reamer is inserted in the fixture with its shank 31 extending throughthe bushing in the headstock and is provided at its outer end with a dog32 engaging a rotatable part 33 of the grinder, so that the reamer willbe continuously rotated during the grinding operation. The dead center13 is adjusted to support the other end of the reamer. The guides 22 areadjusted so that a very light cut will be taken off the cutting edge ofthe blades, and guide 27 and pivot 24 are adjusted so that strut will beengaged by the tooth opposite that being ground at about the time thelatter comes in contact with the grinding wheel, and at such an anglethat the downward motion of the strut Will cause it to be roel-:ed tothe left, as shown inl the drawings, to clear the edge of the toothengaged when the opposite tooth has been groundl across its entirewidth.

The grinding wheel 11 Vis now set in rotation,l as is the rotating part33 and consequently the reamer, and the-feed by which the grinding wheeland reamer are moved longi tudinally or axially of the grinding wheelrelative each other is also thrown in.

Asthe rea-mer rotates, teeth are successively brought into Contact withthe grinding wheel and as each tooth engages the grinding wheel, ,thehead and foot stock start their movement toward the grinding wheel underthe downward pressure of the opposite tooth Vupon thestrut and thecorresponding motion of the stocks produced through the levers, linksand cranks.

Assoon as the grinding .wheel has traversed the entire. width of thetooth being ground, the actuating strut slips off the opposite tooth andsprings 17 and 30 return the part-s to their original positionwhere thefeed will be repeated by the succeeding tooth.

While I have described the illustrated embodiment of my invention insome particularity, obviously many modifications and variations willreadily occur to those skilled in the art, and I do not, therefore,limit myself to the precise details shown and described, but claim as myAinvention all the embodiments thereof coming within the scope of theap,- pended claims. Y

I claim:

1; In combination with a grinder, a pivoted headstock andapivotedfootstock for supporting a multi-bladedcutter adjacent to thegrinding' wheel, feed mechanism for rocking said stocks toward thegrinding wheel, a strutengageable successively with the teeth ofthecutterandy transmitting motion received therefromjto the feed mecha*nism, means forrotating the cutter, and

grinding Wheel, a support for a multi-blader] cutter adjacent theretoand arran ed to support the cutter with its axis para e1 to that of thegrinding wheel, means for rotating the cutter, means for axiallytranslating the cutter and grinding wheel relative to each other, and afeed actuated by successive teeth of the cutter moving the same towardthe grinding wheel.

4. A fixture for grinders which comprises pivoted to said headstock andfootstock at one end and having their other ends slidable in saidguides, a strut engageable by the blades of the cutter opposite theirpoint of Contact with the grinding Wheel, link-work between said strutand arms causing the armste, travel along said guides as the strut ismoved by a blade of the cutter, and spring means returning said arms,strut and associated mechanism to their original osition when the strutpasses the edge of a lade.

In testimony whereof I hereunto afix my signature this 16th day of June,1927.

PATRICK T. LENNON.

a base adapted to be supported upon the table of a grinder, a supportfor a multi-bladed tool movably carried by said base and rotatablysupporting the tool, and feed means moving the support toward thegrinding wheel and actuated by the blade of the tool diametricallyopposite that being ground.

5. In combination with a grinding mechanism including a grinding wheel,a support for a multi-bladed cutter adjacent the gr1nding wheel, meansfor rotating the cutter, means successively engaging the blades of thecutter diametrically opposite the grinding wheel,motion-transmitting-mechanism associated therewith moving the cuttertoward the grinding wheel, and resilient means withdrawing said bladeengaging means to its original position and constituting a reverse feed.

6. A fixture for use on a grinder having a grinding wheel whichcomprises a base adapted to be carried by the table of the grinder, aheadstock and a footstock pivoted to said base to support a multi-bladedcutter adjacent the grinding Wheel, feed mechanism for rocking saidstocks toward the grinding wheel, a strut engageable successively withthe blades of the cutter opposite the point of contact of the cutterwith the grinding Wheel, and transmitting motion received from saidblades to a feed mechanism, means for rotating the cutter and resilientmeans for returning said feed means to its original position away fromthe grinding Wheel when Y the strut is released by a blade of thecutter. f

7. A fixture for use on a grinder having a grinding wheel comprising abase adapted to be secured to the lmovable table of the grinder, aheadstock and footstock pivoted thereto and adapted to support amulti-bladed cutter, guides adjustably carried by said base, arms Y co

